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cold heater
- Thread starter DARKFLY
- Start date
PaulJ
NAXJA Forum User
- Location
- Lynnwood, WA
The heater core has a tendancy to plug up. If that's your problem, you can clear it out by back flushing it with a gardern hose. If the engine is running cold, then you need a new thermostat. OEM is best and runs about $10.
HossHoffer
NAXJA Forum User
- Location
- Aurora, CO
Flush
Paul's got it. These cores plug up badly and you will be suprised how much crud comes out. Start with a back flush and then go each side back and forth. 'Stat sounds fine.
Paul's got it. These cores plug up badly and you will be suprised how much crud comes out. Start with a back flush and then go each side back and forth. 'Stat sounds fine.
5-90
NAXJA Forum User
- Location
- Hammerspace
Two things I'd check -
1) Flush the heater core. Hell, backflush the whole system, since you have to open it up anyhow.
2) Check to make sure the heater control valve hasn't fozen shut on you, or that it isn't getting vacuum. Those can fail after a while, and if the valve freezes shut, the heater core won't get hot water and you won't get hot air...
5-90
1) Flush the heater core. Hell, backflush the whole system, since you have to open it up anyhow.
2) Check to make sure the heater control valve hasn't fozen shut on you, or that it isn't getting vacuum. Those can fail after a while, and if the valve freezes shut, the heater core won't get hot water and you won't get hot air...
5-90
pancake
NAXJA Forum User
- Location
- Seattle, WA
flush heater core only...just use existing heater hoses and make it work. 
Sounds like your thermostat is opening up about the right time (210*) but it is staying open. When it sticks open, the coolant isn't staying in the block long enough to heat up to normal operating temperature. Sounds like you need to replace the thermostat.
This of course won't cure the no heat issue. The back flush should and like 5-90 says, make sure you've got vacuum at the heater valve and it is actually working.
Where in Utah are you?
This of course won't cure the no heat issue. The back flush should and like 5-90 says, make sure you've got vacuum at the heater valve and it is actually working.
Where in Utah are you?
mudhound32
NAXJA Forum User
- Location
- Long Island NY
I agree with Ace, this sounds like the thermostat is partially working. It should be replaced and is not a big deal to do. I would also recommend flushing the system. When was the last time you really flushed the system? I hadn't done my '89 in 2 years and it started blowing cold last winter. So I finally backflushed the entire system and now have alot more heat. You can check out Craig's webpage http://www.olypen.com/craigh/heater.htm that has a good way to backflush the heater core. If this dosen't help you may need to replace the core.
